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CLEVELAND
– A Case Western Reserve University engineer has created
the "seeds" that can grow into today's and
tomorrow's computer and phone chips.
In
a development that could lead to smaller but more
powerful computers and electronic communication devices,
Massood Tabib-Azar, a professor of electrical engineering
and computer science at Case, and engineering graduate
student Yan Xie are growing carbon nanotube bridges
in their lab that automatically attach themselves
to other components without the help of an applied
electrical current.
Carbon
nanotubes, discovered just 14 years ago, are stronger
than steel and as flexible as plastic, conduct energy
better than almost any material ever discovered and
can be made from ordinary raw materials such as methane
gas. In a relatively short time, carbon nanotubes
– thin tubes of carbon atoms that have unusual characteristics
because of their unique structure – have emerged as
a "miracle material" that could revolutionize
a number of industries, especially the small electronics
industry.
What
makes this discovery significant, Tabib-Azar says,
is that, while there are some technical issues yet
to be addressed, carbon nanotube bridges may open
the door for manufacturers to utilize carbon nanotubes
in building the tiniest computer and communication
chips. Carbon nanotubes are being explored for many
applications in nanoelectronics, nano-electromechanical
systems, biosensors, nano-composites, advanced functional
materials and meta-materials.
New
and cheaper ways to grow carbon nanotubes can improve
companies' competitive edge, says Tabib-Azar. The
researchers' method is much less expensive and quicker
to perform and results in a self-assembled network
of carbon nanotube devices.
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| Tabib-Azar
likens making today's computer and cell phone chips
to building a table by chopping down a tree and eliminating
the unwanted portions until you end up with a flat surface
with four legs. He and Xie discovered that you can grow
building blocks of ultra large scale integrated circuits
by growing self-assembled and self-welded carbon nanotubes
much the same way you'd build that table. However, instead
of chopping down the whole tree, all you have to do
is create the "seeds" to grow what you need.
In other words, Tabib-Azar and Xie have found the seeds
to grow just the carbon nanotubes that are needed without
wasting the entire "tree."
"Our
approach is like growing a table using a 'table seed,'
said Tabib-Azar. "By growing the electronic circuits
rather than chopping down and eliminating unwanted
regions of different layers, our approach has the
potential of producing very complex chips with superior
computational properties and at the same time being
less wasteful and more in tune with the way nature
'builds' complex structures."
"Electronics
is at the heart of global competition among superpowers,"
he continued. "And it's important to note that
the electronics world market is an $850 billion industry."
Tabib-Azar
predicts that within five to 10 years the United States'
ability to double the number of switches per chip
every 18 months will be diminished if American electronics
companies don't remain competitive.
In
order to use carbon nanotubes in electronics where
they may greatly benefit device performance and enable
cramming in more devices per chip, the nanotubes should
be connected to electrical contacts. Until now, the
researchers say, to connect carbon nanotubes to electrical
contacts, very high precision tools such as atomic
force microscopes were used that made the resulting
devices very expensive. Or, in the past, researchers
have used electric forces to grow carbon nanotubes
between two contacts. Both these techniques result
in a very few devices and can't be used for producing
a large number of switches and devices in a cost-effective
way.
"There
are many research efforts in the U.S. and across the
world to invent and discover the transistors and switches
that will be more suitable to chips used in cell phones
and computers beyond 2010-2015," said Tabib-Azar.
"Carbon nanotubes have emerged as one of the
candidates to carry the electronics industry forward."
The research is partially supported by the National
Science Foundation's NER Program, the Semiconductor
Research Corp. and the National Institute of Standards
and Technology.
About
the Case School of Engineering
The Case School of Engineering, which is celebrating
its 125th anniversary in 2005, has distinctive and
acclaimed research programs, including biomedical
engineering, functional polymers, fuel cells, advanced
materials, microgravity fluid flow and combustion,
biologically inspired robots, sensors and microfabrication.
Research awards at the school have more than doubled
since 2001 to nearly $60 million.
About
Case Western Reserve University
Case is among the nation's leading research institutions.
Founded in 1826 and shaped by the unique merger of
the Case Institute of Technology and Western Reserve
University, Case is distinguished by its strengths
in education, research, service, and experiential
learning. Located in Cleveland, Case offers nationally
recognized programs in the Arts and Sciences, Dental
Medicine, Engineering, Law, Management, Medicine,
Nursing, and Social Sciences. http://www.case.edu.
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